The Tamiya 70171 3 mm Threaded Shaft Set includes two 3 x 150 mm threaded shafts that can be cut to desired lengths and used to mount pulleys. Also included are six ball joints, four ball connector nuts, and four screws that can be used with the shafts to make control rods with three-dimensional movement. The 3 mm diameter of the shafts, screws, and ball nuts make this set compatible with many Tamiya products.